Aluminium Beam Design
Aluminium Beam Design
(OP)
I've read through our Aluminium Code here in Australia (AS1664.1), and it isn't clear what-so-ever. Not much time has gone into writing it.
Anyway, I've never specified/designed Aluminium before.
I have a small roof to do. Rafters are Aluminium RHS, with Al. RHS struts inbetween like blocking. Basically it won't buckle.
Can I design it as per normal Mild Steel? I.e. Just calculate the stresses in the extreme fibres and ensure it doesn't yeild?
Or am I missing something important?
Obviously E and yeild stress is different, but Ixx etc shouldn't be any different.
Ben
Anyway, I've never specified/designed Aluminium before.
I have a small roof to do. Rafters are Aluminium RHS, with Al. RHS struts inbetween like blocking. Basically it won't buckle.
Can I design it as per normal Mild Steel? I.e. Just calculate the stresses in the extreme fibres and ensure it doesn't yeild?
Or am I missing something important?
Obviously E and yeild stress is different, but Ixx etc shouldn't be any different.
Ben






RE: Aluminium Beam Design
RE: Aluminium Beam Design
RE: Aluminium Beam Design
Again this is a different code, and possibly outdated... I would be leery of treating AL as mild steel, if it was that simple then they wouldn't need beam equations in the AL design manual, right?
RE: Aluminium Beam Design
example calculations for a channel.
RE: Aluminium Beam Design
Do you make all of those MatchCADS? or is there some share site like steeltools for excel programs?
RE: Aluminium Beam Design
It's using Mathcad 15 but I printed it as a .pdf so Ben can view it in case he doesn't have Mathcad.
RE: Aluminium Beam Design
RE: Aluminium Beam Design
In my case I basically have a small roof that is pretty braced out, so a simple flange yield check and acceptable deflections and I'm good to go. Forces are very low.
One thing they don't explain at all as far as I can tell, is what is meant by "Intercept", "Slope" and "Intersection" values. Stupid question I should know or something not explained too well?
RE: Aluminium Beam Design
RE: Aluminium Beam Design
The constants are for different strength curves for each temper of aluminum.
An aluminum construction manual from 1967 is available online here https://law.resource.org/pub/us/cfr/ibr/001/aa.con...
it hasn't changed much at all (I've only gone through it briefly, but I didn't see anything.)